I love the new sounds, but there is one thing that irritates me a little bit.

In LFS when the cars are accellerating we can hear that the drive train squeal is getting a higher tone (or what ever it is called), but when we shift up we can hear that the noise is getting lower again, just like the engine torque.

But thats not what it does in real life?

Atleast not according to this, here the squeal just gets higher and higher, relative to his speed, and not his revs.

http://video.google.com/videop ... mp;q=bmw+nordschleife+gtr

Quote from MyBoss :

here the squeal just gets higher and higher, relative to his speed, and not his revs.

That's what my copy of LFS does...

Its affected by both. Its a pretty complex thing. The reason for the sound drop is a drop in torque. If you keep your foot on the throttle just enough to sustain speed, you should hear less gear whine etc. which LFS models correctly. I think the diff noise is pretty damn good for a synth.

Well, I don't know the specifics of how it's modelled in LFS since Scawen has not said. However, you really get two sounds - where the transmission sound will change with engine revs to some degree (because the input shaft is connected directly to the engine) but also change because the speed of the output shaft increases with each gear. It's not a simple sound... I guess you could do some basic math & figure out which frequencies should be generated.

The differential will keep increasing in pitch since it's one ratio continues to increase in rotational speed.

speaking of all of this, it seems to be much mcuh louder when in reverse too

Quote from XCNuse :

speaking of all of this, it seems to be much mcuh louder when in reverse too

yea I noticed this too

Quote from XCNuse :

speaking of all of this, it seems to be much mcuh louder when in reverse too

Regarding reversing, how come (in your usual everyday car of course!) the car's engine/gearbox always sounds louder when reversing?

Is that gearbox whine or what?

That is gearbox whine, in reverse in a real car. Those of you that also race RC cars and have for some time probaly also know the gear pitch also playes a big part in the sound generated from a gearset. Lower pitch gears make more noise. Its possible that the reversing gearset is just a low pitch set for high strength and not ment to be run very fast.

Quote from Mikkel Petersen :

Regarding reversing, how come (in your usual everyday car of course!) the car's engine/gearbox always sounds louder when reversing?

Is that gearbox whine or what?

I think I read something like the following on howstuffworks.com, you can check if you like:
The forward gears are helical cut (the teeth are conected via a greater surface) thus reducing the noise of them turning against each other. While driving forward, all the forward gears are always engaged, only the output shaft is connected to different gears to change ratios. To engage reverse, you have to disengage alle the forward gears and engage another part of the transmission, which obviously has to be disconnected from the forward gears. You can't simply engage and disengage helical gears (look up a picture to understand) so to engage reverse, actually two _straight_ cut gears engage, which produce a lot of noise when turning against each other.

Hope this is correct and understandable

- ben

Quote from Mikkel Petersen :

Regarding reversing, how come (in your usual everyday car of course!) the car's engine/gearbox always sounds louder when reversing?

Is that gearbox whine or what?

lol i wouldn't know, i can't say i've ever heard my gearbox ever whine, or any car i've ever been in have i ever heard one whine

edit- well that clears it up, thanks ben

Quote from XCNuse :

lol i wouldn't know, i can't say i've ever heard my gearbox ever whine, or any car i've ever been in have i ever heard one whine

edit- well that clears it up, thanks ben

Ever driven a manual though? I don't know what autos sound like reversing but it's a very definate effect in manuals, quite why I can't tell you but the explination of it being a straight cut gear sounds about right.

I can hear gear whine clearly in my '90 Fiat Uno. Also in our Opel Astra, you can't hear it while driving, but when doing some engine braking by switching down gears, you can hear it a little bit.

The reverse gear whine sounds pretty similar to my old Micra's gearbox. Its a nice touch.

I've not noticed much gear whine in the C4 I drive at the min either forward or reverse. Maybe because its an auto, or because its a lot newer.

simply put straight cut gears are cheaper but break sooner ... and since you normaly dont spend much time or dont drive very fast in reverse straight cuts are used for the reverse gears

^^ Don't think it's true that straight cut gears always break quicker, they are a lot more efficent but also far noiser.

Quote from ajp71 :

^^ Don't think it's true that straight cut gears always break quicker, they are a lot more efficent but also far noiser.

have you ever thought about what causes the noise and how its related to additional stress on the cogs ?

Quote from Shotglass :

have you ever thought about what causes the noise and how its related to additional stress on the cogs ?

Right, well it just depends on how you want them to break. If you want more heat and wrecked thrust bearings because of the wasteful other forces involved, then helical is the way to go. By their nature there is more loss. Straight cut gears are cheap for sure, are far better for transferring massive loads for a long period of time, over and over. Just plain noisy.

Quote from Ball Bearing Turbo :

Straight cut gears are cheap for sure, are far better for transferring massive loads for a long period of time, over and over.

dont think so ... more like suited to transfer torque if wear isnt an issue
massive amounts of torque over extended periods of time like on ship engines afaik are usually transfered using double helical gears

Is it not because of the synchromesh in reverse that causes the different sound?

Quote from viper-gt :

Is it not because of the synchromesh in reverse that causes the different sound?

rather no synchromesh in reverse...
but noise is more due to straight cut cogs what you hear in GTRs

Quote from viper-gt :

Is it not because of the synchromesh in reverse that causes the different sound?

no the synchromesh in reverse (or rather the lack thereof) is what causes the grinding noise when you shift to reverse while the car is still in motion

edit: one thing currently missing with the transmission whine in that it doesnt change pitch with final drive settings

In a normal car, the reverse gear is usually a straight cut gear. Your normal 1-5 gears are not straight cut, they have an angle to them. Straight cut gears are stronger and hold better. Races cars will most of the time have a trans called a 'dog box' which uses straight cut gears and uses a different method of transfering gears other then the synchros you would find in a standard transmission.

As for the sounds in LFS, I havent really paid attention in LFS to see if they are normal :P

What better way tehn with an illustration. Top two gears are helical and bottom is straight cut.



As you can see the way the gears 'lock on' to each other would make a different noise.